Forms of address for government officials and others
are posted by InfoPlease, Dictionary.com and other sites. You can also find Forms of Address in the back of The Federal-State-Local Government Directory, the New York Public Library Desk Reference and any good desk manual for secretaries. For the U.K. and other countries (including the U.S.), use Debrett's Online or an old print edition of Debrett's Correct Form (available from Amazon.com and other online booksellers).